1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) having an enhanced display quality.
2. Description of the Related Art
Liquid crystal displays (LCDs) include a liquid crystal panel equipped with a plurality of gate lines and a plurality of data lines, a gate driving unit which outputs a gate signal to the gate lines, and a data driving unit which outputs a data signal to the data lines. In order to reduce the size and enhance the manufacturability of LCDs, gate drivers are integrated in a peripheral area of the LCD panel. A gate driving unit is formed on the LCD panel that includes a plurality of stages for sequentially outputting gate signals. Each of the stages includes at least one amorphous silicon thin film transistor (a-Si TFT). The a-Si TFT receives first and second clock signals and outputs a gate signal. The driving capability of an a-Si TFT varies according to the ambient temperature, the driving capability of an a-Si TFT decreasing with ambient temperature.
When the temperature is very low, an a-Si TFT may not be able to output a gate signal having a sufficient voltage to turn on or off the switching device for a pixel. Therefore, in order to enhance the driving capability of the a-Si TFT at low temperatures, the amplitudes of the first and second clock signals are increased. Given that the first and second clock signals swing between a gate-on voltage and a gate-off voltage, the gate-off voltage is reduced in order to increase the amplitudes of the first and second clock signals.
Conventionally, a decrease in a gate-off voltage causes an image sticking, thereby adversely affecting display quality. Therefore, it is necessary to enhance the driving capability of an a-Si TFT at low temperatures and decrease the after-image.